DOWER HOUSE

A 'dower house' is usually a moderately large house on an estate which is occupied by the widow of the late owner. The widow, often known as the "dowager" usually moves into the dower house, from the larger family house, on the death of her husband, the new heir occupies the now vacated principal house.
In the case of the British royal family there is a dower house in London as well as the country. Well known royal dower houses in London have been Clarence House, Marlborough House, and for a brief period Buckingham Palace then known as Buckingham House. Frogmore House has served as Windsor Castle's dower house.